Iran's caviar output has been declining since the early 1990s, when about 300 tons was harvested. Last year, Iran's caviar output was just over 90 tons.

Iran and Russia, the world's other major caviar producer, have pledged to fight against illegal harvesting, which accounts for between seven and eight tonnes of the caviar on the market, Jalili said.

The breakup of the Soviet Union, which tightly regulated its caviar industry, created three new Caspian countries -- Azerbaijan, Kazakhstan and Turkmenistan. Iran says they have developed their own caviar industries without precautions.

In particular, they have failed to check illegal fishing and allowed nets of too small a mesh, bringing the sea's sturgeon population down from 200 million in 1990 to 60 million five years later.

The Caspian's resources have also been harmed by pollution from the sea's growing oil industry.

Iran released about 25 million sturgeon fry into the sea this year and tries to protect the young population by banning fine fishing nets - TEHRAN (AFP)